Konigswerk Wood Grain LED Alarm Clock - Time Temperature Date - Display Sound Activated - Auto Brightness Adjustment (Brown-Red) AC021G Modern Wood Grain Thermometer Touch Sound Activated Desk LED Digital Alarm Clock (Powered by: AAA Battery / USB / DC) (AAA battery not included) Display can be set to be Sound activated. Sound activated mode display will turn off after 15 seconds (Clock's still working). You clap hands/make a sound/simply touch the clock to activate the display to read time. AAA batteries and USB/DC power supply can be used simultaneously, and batteries act as a backup. If LED display keeps ON and only powered by batteries, battery is easy to waste (Works around 3 days). Please use the USB cable replaces the batteries to charge your clock. New Version LED Display Auto Brightness: display auto dim after 22:00, comfortable brightness at night Clear LED Display: Time (12/24 hrs) and Temperature ( C/ F),Clear and bright display shows Time and Temperature, You could choose 12 / 24hr or C/ F.